Solenoid



June e, 1944. H` T; SPARRQW 2,350,938

SOLENOID Filed July 2. 1942 7@ im Y INVENTOR. Home??? 7.' iw

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HT/Vf'y Patented June 6, 1944 UNITED STATES PAT'ENT-OFFICE SOLENOID Y Hubert T. Sparrow, Minneapolis, Minn., assigner to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application July 2, 1942, serial No. 449,461

14 claims.

Thisy invention relates to al relatively light,

powerful and compact solenoid that is both efficient and positive ingoperation. In particular, the invention relates to a solenoid for the positive operation of various types of devices under adverse conditions,` including` the existence of considerable vibration, and the `device of the invention isespecially adapted for use with aircraft.V An object of the invention is the provision of a switch in whichv the motion of a switch operating member isI transmitted to a'dielectric uid for the hydraulicoperation of a switching mechanism and in which thecontact members of the switching mechanism are mounted in the dielectric hydraulic fluid.

A further object of the invention is to provide for the operation by an electromagnet of a hydraulically actuated switch and in the provision of means for restrictingthe now of the hydraulic uid to provide a predetermined time delay in the operation of the switch following eachinitial operation of the electromagnet.

A particular object of the invention is the provision of a solenoid having an armature for the operation of a device and also for the opera- Ition of a switch together with the provision of a timing mechanism for operating the switch at a predeterminedy period following each initial energization of the armature in combination with means providing for the rapid operation of the switch following each deenergization of the solenoid jand the accompanying operation of the armature.

In greater detail, my invention relates to ay solenoid in which a'flrst circuit employing a relatively high current is provided for each initial operation of the solenoid and where upon the lapse of a predetermined period operation of the solenoid 'is maintained by a second circuit in which the current and power required to operate the solenoid is substantially reduced.

' Additional objects, advantages and vfeatures of the invention will be apparent by reference to the following detailed description of one application of 'my invention together with the accompanying drawing and claims.

The drawing illustrates a vertical sectional view, partly diagrammatic,cf a solenoid of my invention together with a schematic illustration of the circuit employed.`

In the. drawingthe solenoid includes a casing of magnetic material to which is threaded a coreand stop member 6. A magnetic sleeve member 1 is also threaded to the casing member 5, and supported upon the stop member 6 is a cylindrical sleeve member 8 of non-magnetic material. An armature I2 is mounted for movement within the cylindrical sleeve member 3 and, as illustrated, is in the deenergized position supported upon the non-magnetic base member I4. Coils I6 and I 'l surroundthe non-magnetic sleeve member 8 and are mounted between the stop member 6 and the sleeve member 1.

An annular opening 2U is formed axially in the upper surface of the stop member 6 and an annular member 2| cooperates with the top of the stop member for securing a diaphragm 22 across the top of opening 2li.` The diaphragm 22 may be of any suitable kind although I preferably employ a crimped metallic material. A plate member 25 ris secured to the disk 2l and together with the diaphragm 22 these members denne a chamber 2li.V Mounted upon the plate 25 is a further annular member 28 of insulating material upon-which is secured a diaphragm 3S. The diaphragm 30 is of a crimped metallic material and forms a portion of 'the electrical circuit as hereinafter described. The plate 25, disk 28 and diaphragm 30f'deiine a chamber 3|. A cover member'BZ provided with openings 33, is placed on top of diaphragm 30 so that this diaphragm is secured between cover member 22 and annular member 28. A passageway 34 is formed in the plate 28 for communication with the chamber `3| and this passageway communicates with a threaded opening 35 in cover member 32. 'I'his opening is closed off by a plug member 36.

The chamber 26 communicates with the chamber 3l through one or more orifice members 40 vformed in the plate 25. A` relatively large opening 4| is also provided in the plate 25 and forms a valve seatwith which a valve 42 cooperates. Th'evalve 42 is supported by a spring 43. This Aspring is secured to the plate 25 and serves to normally'maintain the valve in the closed position. l

fswitch contact 44 is mounted upon the plate 25,.for cooperation with a second contact 45 .that `ismounted on the metallic diaphragm 30. A threaded sleeve member 41 is mounted upon .the plate 32 and, together with an opening 48 in the plate, formsl a passageway in which is mcviunted a spring 49 for biasing the diaphragm 30 ina direction to close the switch contacts. A screwA having a knurled head, is mounted for adjustment within the threaded sleeve member 4'!4 and ,one end of the biasing spring 49 is engaged by the screw to thus provide for selectively varying the bias exerted by the spring and metallic diaphragm upon the switch Contact 46.

A dielectric and hydraulic uid is admitted to the communicating chambers 26 and 3l through the passageway 34 and the plug member 36 serves to seal the fluid within the two chambers. It will be noted that when the chambers are supplied with fluid care should preferably be taken to do so in a manner that will insure against the admission of air to the chambers in order to minimize the eiects of varying altitudes and temperatures upon the operation of the switch.

The armature I2 has a central passageway 55 formed in the upper end that communicates with an enlarged central passageway 56 also formed in the armature. A piston member 51 is movable within the passage 55 and has an enlarged head portion 58 that is movable within the passageway 56. A spring 59 serves to bias the piston head against the shoulders of the armature that dene the passageway 55. The piston 51 extends through a passage 54 formed in the stop member 5 and has a threaded end portion 60 of reduced diameter' that is secured to the diaphragm by a nut 6I and washer members 62, Threadedly secured to the lower end of the armature is a member 65 having a head portion 66 to which is secured an attachment member 61 for the operation of a valve, switch or other type of' device, not shown. The head 66 of the member 65 serves to support and guide `one end of a spring 68, the other end of which bears against the base member I4. This spring 68 is employed to bias the armature member to the deenergized position.

The coil I6 is preferably formed of low resistance wire having relatively few turns and the coil I1 is formed of a relatively large number of turns of high resistance wire. When the solenoid is energized, as `by operation of 'a switch 12, a circuit is initially completed which includes battery 16, a conductor 1I, switch 12, a conductor 13, terminal 14, the coil I6, terminal 15, conductor 16, switch contacts 44 and 46, metallic diaphragm Si), plate 32, grounded conductor 11, and conductor 18 for return to the battery 10. Upon the completion of this circuit a relatively large current is established lto produce a relatively large magnetomotive force in the magnetic circuit of the solenoid. The magnetic circuit of the solenoid includes the stop member II, casing member 5, the sleeve member 1,and the armature I2. This magnetomotive force provides for the positive and rapid operation of the armature I2 to the energized position in which the armature contacts the stop member 6. At this time, following the operation of the armature, the piston member 61 is operated by the biasing spring 5B in an upward'direction to also provide for the movement ci the diaphragm 22 in an upward direction. The hydraulic iiuid contained in the chamber 26 accordingly is forced through the orice ow restricting member 4i! to the upper chamber 3|. Suiicient fluid is forced from the chamber 26 to the chamber 3I a predetermined period following the operation of the armature to operate the diaphragm 3G in an upward direction for opening the switch contacts 44 and 46. The time required for the fluid to open the switch contacts 44 and i6 is largely determined by the orice member or members 40 and may also be varied by adjustment of the diaphragm biasing spring 49.

The opening operation of the switch contacts 44 and 46 serves to remove a shunt from around coil I1 to establish the following ciircuit: battery 1Q, conductor 1I, switch 12, conductor 13, terminal 14, coil I6, the common terminal 15 for the coils I6 and I1, terminal 82 of the coil I1, conductor 83, and the grounded conductor 18 back to the battery 1D. The completion of this circuit which includes each of the coils I6 and I1 serves to increase the resistance inserted in the circuit to provide for a reduction in current and the corresponding reduction in power required for the continued operation of the solenoid.

When the solenoid is deenergized by operation of the switch 12, the armature I2 is rapidly returned to the position illustrated in the drawing by operation of the biasing spring 68 and by the force of gravity. This operation of the armature serves to rapidly move the piston 51 and diaphragm 22 in a downward direction. Rapid movement in the downward direction takes place since the fluid returning to the chamber 26 is permitted to ilow not only through the orice 40, but also through the opening 4l which is normally closed by operation of the biased valve 42. The valve 42 is opened in response to the increased differential in pressure between the fluid in the two chambers by reason of the downward operation of the diaphragm.

It is accordingly apparent that in the initial energization of the solenoid, a relatively large magnetic force is established to provide for the rapid and positive operation of the armature. This force is continued for a predetermined period after which the switch contacts 44 and 46 are operated to alter the solenoid circuit and decrease the power required for maintaining the solenoid in its energized or operating position. Upon deenergization of the solenoid it is also apparent that the valve member 42 operates to remove any substantial restriction to the flow of fluid between the chambers 3l and 26 and to thus provide for the rapid closure of the switch contacts 44 and 46 and the rapid downward movement of the armature I2.

In the operation of my switch, it will be observed that the adjustable biasing spring 49 may be omitted where a metallic diaphragm is employed that is otherwise capable of operation in a satisfactory manner, and also that diaphragms may be selected which will be more or less rapid in the operation of the switch contacts.

Provision is made for the automatic compensation of the switch of my invention for changes in ambient pressure or altitude by subjecting one side of eaehof the diaphragme 22 and 30 to the ambient conditions in conjunction with the substantial exclusion of air from the fluid chambers. In addition, the hydraulic uid employed in the chambers 26 and 3| is preferably of a type in which the temperature characteristics are such as to insure the proper operation of the switching mechanism throughout the relatively very wide range of temperatures to which the solenoid may be subjected.

It will be apparent that the electromagnetically actuated hydraulic switch of my invention isV I claim as my invention: y Y

1. In an electromagnetic device, in combination, an electromagnet, an armature, a load operated thereby and means including timing means for decreasing the curr-ent flow through the energizing means of the electromagnet at a predetermined periodfollowingeach initial energization of such means and operation of the armature to its fully attracted position.

2. In an electromagnetic device, in combination, an electromagnet including an armature and energizing means, means including timing means for decreasing the current flow through theV ener- `gizing means of the electromagnet at a predetermined period following each initial energization of the energizing means and operation of the armature to its fully attracted position, and means operativev simultaneously with the deenergization of the energizing means and armature to rapidly provide for the subsequent energization of the energizing means and armature at the original current flow.

3. In an electromagnetic device, in combination, electromagnetic means including an armature and a winding, means including hydraulically operated timing means for decreasing the current flow through the energizing winding of the electromagnetic means at a predetermined period following the energization of the winding and consequent operation of the armature, and means simultaneously operative with the deenergization of the winding to rapidly provide for the subsequent energization of the winding at the original rate.

4. In combination, a solenoid, a first circuit for the relatively high supply of power to initially energize the solenoid, a second circuit for maintaining the energization of the solenoid, a switch for transferring the control of the solenoid from the rst circuit to the second circuit, timer means for delaying the operation of the switch for a predetermined period following each initial energization of the solenoid, and means for the rapid operation of the switch to its original position upon deenergization of the solenoid.

5. In combination, a solenoid, a circuit for the supply of power to initially operate the solenoid in a rapid and positive manner, a circuit for maintaining energization of the solenoid, a switch actuated by the solenoid for transferring energization of the solenoid from the first circuit to the second circuit, and time delay means for assuring the positive initial operation of the solenoid bythe first circuit before operation of the switch for transferring the operation of the solenoid to the said second circuit.

6. In combination, a first circuit and a second circuit, a switch for controlling said circuits, electromagnetic actuating means included in each of said circuits for controlling an armature, a switch operated upon movement of the armature, and means for causing a time delay between operation of the armature to its fully attracted position by the electromagnetic means and the operation of the switch.

7. In combination, a solenoid, an armature, a switch, a first circuit of relatively high power for initially energizing the solenoid, a second circuit of relatively low power for maintaining the energization of the solenoid, and time delay switch operating means for transferring the control of the solenoid from the first circuit to the second circuit after movement of the armature to its fully attracted position.

8. In combination, a main circuit and a main switch in control ofsaid circuit, electromagnetic means having an armature and a circuit including a winding associated with the main circuit, a switch operated by the electromagnetic means for varying the main circuit and timer means for delaying the operation of the switch in one manner for a predetermined period following each initial energization of the electromagnetic means under the control of the main switch.

9. In combination, a hydraulic chamber and a first diaphragm forming a part thereof, a second hydraulic chamber and a second kdiaphragm forming a part thereof, a fluid in said chambers, switch means actuated vby the said first diap hragm, orice means between the first and second chambers for 'restricting the flow of fluid between the first and secondV chambers, and

' means moving the second diaphragm to control the fiuid in the rst and second chambers to operate the switch.

10. In combination, a first hydraulic chamber and a first diaphragm forming a part thereof, a second hydraulic chamber and a second diaphragm forming a part thereof, switch means actuated by the said first diaphragm, means including orifice means between the first and second chambers for restricting the flow of fluid between the first and second chambers, plunger means for operating the second diaphragm to control the fluid in the first and second chambers for operating the switch, electromagnetic means for actuating the plunger including an armature having a chamber within which one end of the plunger means is movable, means within the armature chamber for biasing the plunger, means for movement in a direction for operating the said second diaphragm and switch in a rst manner at a predetermined period following each initial energization of the electromagnetic means, said armature including means for the rapid operation of the plunger and second diaphragm in a second manner when the electromagnetic means is deenergized, and means providing for the substantially unrestricted ow of fluid from the rst hydraulic chamber to the second hydraulic chamber when the armature and electromagnetic means are deenergized for the rapid operation of the switch in a second manner.

11. In an electromagnetic device, in combinanation, electromagnetic means including an armature and a winding, hydraulically operated time delay means for decreasing the current ow through the energizing .winding of the electromagnetic means at a predetermined period following actuation of said time delay means, and means operated by said armature upon movement to its actuated position for actuating said time delay means.

12. In combination, a solenoid, a iirst circuit for the relatively high supply of power to initially energize the solenoid, a second circuit for maintaining the energization of the solenoid, a switch for transferring the control of the solenoid from the first circuit to the second circuit, hydraulically operated timer means for delaying the operation of the switch for a predetermined period following the initial energization of the solenoid, and means for the rapid operation of the switch to its original position upon deenergization of the solenoid.

13. In combination, a solenoid, an armature actuated thereby, a first circuit for the relatively high supply of power to initially energize the solenoid, a second circuit for maintaining the energization of the solenoid, a switch for transferring the control of the solenoid from the rst circuit to the second circuit, hydraulically operated timer means including a rst chamber and a first diaphragm, a second chamber and a second diaphragm, a fluid in said chambers, orifice means between the first and second chambers for restricting the iiow of fluid between the rst and second chambers, connections between said armature and the first diaphragm for owing uid from the rst chamber to the second chamber to move the second diaphragm to operate the switch for transferring the control of the solenoid from the iirst circuit to the second circuit upon attraction of said armature.

14. In combination, a solenoid, an armature actuated thereby, a rst circuit for the relatively high supply of power to initially energize the solenoid, a second circuit for maintaining the energization of the solenoid, a switch for transferring the control of the solenoid from the first circuit to the second circuit, hydraulically operated timer means including a first chamber and a first diaphragm connected to said armature for actuation thereby when attracted to said solenoid, a second chamber and a second diaphragm, a fluid in said chambers, orifice means between the rst and second chambers for restricting the flow of fluid between the rst and second chambers upon actuation of the irst diaphragm by the armature for flowing uid from the first chamber to the second chamber to move the second diaphragm for operating the switch and transferring the control of the solenoid from the first circuit to the second circuit, and means for the rapid operation of the switch to its original position upon deenergization of the solenoid.

HUBERT T. SPARROW.

CERTIFICATE OF CORRECTION.

Patent No. 2,550,958. June 6, 191m.

HUBERT T. sPARRow.

It is hereby certified that error appears the printed specification of the above numbered patent requiring correction as follows: Page l, second column, line 28, for "member 22" read --member 52"; 1page 2, first column, line 214, after "diaphragm" insert the numeral -22; page l1., 4first column, line 114, claim 13, after "armature" insert --by said solenoid; and that thel said Letters rPatent should be read with this correction therein that the same mayV conform to the record of the case in the Patent Office.

signed and sealed this 26th day of september, A. D. 191m.

Leslie Frazer (Seal) Acting Comissioner of Patents. 

